/*
 * Symphony - A modern community (forum/SNS/blog) platform written in Java.
 * Copyright (C) 2012-2018,  b3log.org & hacpai.com
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
package org.b3log.symphony.event;

import org.apache.commons.lang.StringUtils;
import org.apache.commons.lang.time.DateFormatUtils;
import org.b3log.latke.Keys;
import org.b3log.latke.event.AbstractEventListener;
import org.b3log.latke.event.Event;
import org.b3log.latke.event.EventException;
import org.b3log.latke.ioc.inject.Inject;
import org.b3log.latke.ioc.inject.Named;
import org.b3log.latke.ioc.inject.Singleton;
import org.b3log.latke.logging.Level;
import org.b3log.latke.logging.Logger;
import org.b3log.latke.model.Pagination;
import org.b3log.latke.model.User;
import org.b3log.latke.repository.*;
import org.b3log.latke.service.LangPropsService;
import org.b3log.symphony.model.*;
import org.b3log.symphony.processor.advice.validate.UserRegisterValidation;
import org.b3log.symphony.processor.channel.ArticleChannel;
import org.b3log.symphony.processor.channel.ArticleListChannel;
import org.b3log.symphony.repository.CommentRepository;
import org.b3log.symphony.repository.UserRepository;
import org.b3log.symphony.service.*;
import org.b3log.symphony.util.*;
import org.json.JSONObject;

import java.util.HashSet;
import java.util.List;
import java.util.Set;

/**
 * Sends a comment notification.
 *
 * @author <a href="http://88250.b3log.org">Liang Ding</a>
 * @version 1.7.12.2, Jan 30, 2018
 * @since 0.2.0
 */
@Named
@Singleton
public class CommentNotifier extends AbstractEventListener<JSONObject> {
	// 添加评论到文章字段，该字段是从EventTypes移动至此
	public static final String ADD_COMMENT_TO_ARTICLE = "Add Comment";

	/**
	 * Logger.
	 */
	private static final Logger LOGGER = Logger.getLogger(CommentNotifier.class);

	/**
	 * Comment repository.
	 */
	@Inject
	private CommentRepository commentRepository;

	/**
	 * User repository.
	 */
	@Inject
	private UserRepository userRepository;

	/**
	 * Notification management service.
	 */
	@Inject
	private NotificationMgmtService notificationMgmtService;

	/**
	 * Article query service.
	 */
	@Inject
	private ArticleQueryService articleQueryService;

	/**
	 * User query service.
	 */
	@Inject
	private UserQueryService userQueryService;

	/**
	 * Avatar query service.
	 */
	@Inject
	private AvatarQueryService avatarQueryService;

	/**
	 * Short link query service.
	 */
	@Inject
	private ShortLinkQueryService shortLinkQueryService;

	/**
	 * Language service.
	 */
	@Inject
	private LangPropsService langPropsService;

	/**
	 * Pointtransfer management service.
	 */
	@Inject
	private PointtransferMgmtService pointtransferMgmtService;

	/**
	 * Comment query service.
	 */
	@Inject
	private CommentQueryService commentQueryService;

	/**
	 * Follow query service.
	 */
	@Inject
	private FollowQueryService followQueryService;

	/**
	 * Role query service.
	 */
	@Inject
	private RoleQueryService roleQueryService;

	@Override
	public void action(final Event<JSONObject> event) throws EventException {
		final JSONObject data = event.getData();
		LOGGER.log(Level.TRACE, "Processing an event [type={0}, data={1}]", event.getType(), data);

		try {
			final JSONObject originalArticle = data.getJSONObject(Article.ARTICLE);
			final JSONObject originalComment = data.getJSONObject(Comment.COMMENT);
			final boolean fromClient = data.optBoolean(Common.FROM_CLIENT);
			final int commentViewMode = data.optInt(UserExt.USER_COMMENT_VIEW_MODE);

			final String articleId = originalArticle.optString(Keys.OBJECT_ID);
			final String commentId = originalComment.optString(Keys.OBJECT_ID);
			final String originalCmtId = originalComment.optString(Comment.COMMENT_ORIGINAL_COMMENT_ID);
			final String commenterId = originalComment.optString(Comment.COMMENT_AUTHOR_ID);

			final String commentContent = originalComment.optString(Comment.COMMENT_CONTENT);
			final JSONObject commenter = userQueryService.getUser(commenterId);
			final String commenterName = commenter.optString(User.USER_NAME);

			// 0. Data channel (WebSocket)
			final JSONObject chData = JSONs.clone(originalComment);
			chData.put(Comment.COMMENT_T_COMMENTER, commenter);
			chData.put(Keys.OBJECT_ID, commentId);
			chData.put(Article.ARTICLE_T_ID, articleId);
			chData.put(Comment.COMMENT_T_ID, commentId);
			chData.put(Comment.COMMENT_ORIGINAL_COMMENT_ID, originalCmtId);

			String originalCmtAuthorId = null;
			if (StringUtils.isNotBlank(originalCmtId)) {
				final Query numQuery = new Query().setPageSize(Integer.MAX_VALUE).setCurrentPageNum(1).setPageCount(1);

				switch (commentViewMode) {
				case UserExt.USER_COMMENT_VIEW_MODE_C_TRADITIONAL:
					numQuery.setFilter(CompositeFilterOperator.and(
							new PropertyFilter(Comment.COMMENT_ON_ARTICLE_ID, FilterOperator.EQUAL, articleId),
							new PropertyFilter(Keys.OBJECT_ID, FilterOperator.LESS_THAN_OR_EQUAL, originalCmtId)))
							.addSort(Keys.OBJECT_ID, SortDirection.ASCENDING);

					break;
				case UserExt.USER_COMMENT_VIEW_MODE_C_REALTIME:
					numQuery.setFilter(CompositeFilterOperator.and(
							new PropertyFilter(Comment.COMMENT_ON_ARTICLE_ID, FilterOperator.EQUAL, articleId),
							new PropertyFilter(Keys.OBJECT_ID, FilterOperator.GREATER_THAN_OR_EQUAL, originalCmtId)))
							.addSort(Keys.OBJECT_ID, SortDirection.DESCENDING);

					break;
				}

				final long num = commentRepository.count(numQuery);
				final int page = (int) ((num / Symphonys.getInt("articleCommentsPageSize")) + 1);
				chData.put(Pagination.PAGINATION_CURRENT_PAGE_NUM, page);

				final JSONObject originalCmt = commentRepository.get(originalCmtId);
				originalCmtAuthorId = originalCmt.optString(Comment.COMMENT_AUTHOR_ID);
				final JSONObject originalCmtAuthor = userRepository.get(originalCmtAuthorId);

				if (Comment.COMMENT_ANONYMOUS_C_PUBLIC == originalCmt.optInt(Comment.COMMENT_ANONYMOUS)) {
					chData.put(Comment.COMMENT_T_ORIGINAL_AUTHOR_THUMBNAIL_URL, avatarQueryService
							.getAvatarURLByUser(UserExt.USER_AVATAR_VIEW_MODE_C_ORIGINAL, originalCmtAuthor, "20"));
				} else {
					chData.put(Comment.COMMENT_T_ORIGINAL_AUTHOR_THUMBNAIL_URL,
							avatarQueryService.getDefaultAvatarURL("20"));
				}
			}

			if (Comment.COMMENT_ANONYMOUS_C_PUBLIC == originalComment.optInt(Comment.COMMENT_ANONYMOUS)) {
				chData.put(Comment.COMMENT_T_AUTHOR_NAME, commenterName);
				chData.put(Comment.COMMENT_T_AUTHOR_THUMBNAIL_URL, avatarQueryService
						.getAvatarURLByUser(UserExt.USER_AVATAR_VIEW_MODE_C_ORIGINAL, commenter, "48"));
			} else {
				chData.put(Comment.COMMENT_T_AUTHOR_NAME, UserExt.ANONYMOUS_USER_NAME);
				chData.put(Comment.COMMENT_T_AUTHOR_THUMBNAIL_URL, avatarQueryService.getDefaultAvatarURL("48"));
			}

			chData.put(Common.THUMBNAIL_UPDATE_TIME, commenter.optLong(UserExt.USER_UPDATE_TIME));
			chData.put(Common.TIME_AGO, langPropsService.get("justNowLabel"));
			chData.put(Comment.COMMENT_CREATE_TIME_STR,
					DateFormatUtils.format(chData.optLong(Comment.COMMENT_CREATE_TIME), "yyyy-MM-dd HH:mm:ss"));
			String thankTemplate = langPropsService.get("thankConfirmLabel");
			thankTemplate = thankTemplate.replace("{point}", String.valueOf(Symphonys.getInt("pointThankComment")))
					.replace("{user}", commenterName);
			chData.put(Comment.COMMENT_T_THANK_LABEL, thankTemplate);
			String cc = shortLinkQueryService.linkArticle(commentContent);
			cc = shortLinkQueryService.linkTag(cc);
			cc = Emotions.toAliases(cc);
			cc = Emotions.convert(cc);
			cc = Markdowns.toHTML(cc);
			cc = Markdowns.clean(cc, "");
			cc = MP3Players.render(cc);
			cc = VideoPlayers.render(cc);

			if (fromClient) {
				// "<i class='ft-small'>by 88250</i>"
				String syncCommenterName = StringUtils.substringAfter(cc, "<i class=\"ft-small\">by ");
				syncCommenterName = StringUtils.substringBefore(syncCommenterName, "</i>");

				if (UserRegisterValidation.invalidUserName(syncCommenterName)) {
					syncCommenterName = UserExt.ANONYMOUS_USER_NAME;
				}

				cc = cc.replaceAll("<i class=\"ft-small\">by .*</i>", "");

				chData.put(Comment.COMMENT_T_AUTHOR_NAME, syncCommenterName);
			}

			chData.put(Comment.COMMENT_CONTENT, cc);
			chData.put(Comment.COMMENT_UA, originalComment.optString(Comment.COMMENT_UA));
			chData.put(Common.FROM_CLIENT, fromClient);

			ArticleChannel.notifyComment(chData);

			// + Article Heat
			final JSONObject articleHeat = new JSONObject();
			articleHeat.put(Article.ARTICLE_T_ID, articleId);
			articleHeat.put(Common.OPERATION, "+");

			ArticleListChannel.notifyHeat(articleHeat);
			ArticleChannel.notifyHeat(articleHeat);

			final boolean isDiscussion = originalArticle
					.optInt(Article.ARTICLE_TYPE) == Article.ARTICLE_TYPE_C_DISCUSSION;
			final String articleAuthorId = originalArticle.optString(Article.ARTICLE_AUTHOR_ID);
			final boolean commenterIsArticleAuthor = articleAuthorId.equals(commenterId);

			final Set<String> requisiteAtParticipantsPermissions = new HashSet<>();
			requisiteAtParticipantsPermissions.add(Permission.PERMISSION_ID_C_COMMON_AT_PARTICIPANTS);
			final boolean hasAtParticipantPerm = roleQueryService.userHasPermissions(commenterId,
					requisiteAtParticipantsPermissions);

			if (hasAtParticipantPerm) {
				// 1. '@participants' Notification
				if (commentContent.contains("@participants ")) {
					final List<JSONObject> participants = articleQueryService.getArticleLatestParticipants(
							UserExt.USER_AVATAR_VIEW_MODE_C_ORIGINAL, articleId, Integer.MAX_VALUE);
					int count = participants.size();
					if (count < 1) {
						return;
					}

					count = 0;
					for (final JSONObject participant : participants) {
						final String participantId = participant.optString(Keys.OBJECT_ID);
						if (participantId.equals(commenterId)) {
							continue;
						}

						count++;

						final JSONObject requestJSONObject = new JSONObject();
						requestJSONObject.put(Notification.NOTIFICATION_USER_ID, participantId);
						requestJSONObject.put(Notification.NOTIFICATION_DATA_ID, commentId);

						notificationMgmtService.addAtNotification(requestJSONObject);
					}

					final int sum = count * Pointtransfer.TRANSFER_SUM_C_AT_PARTICIPANTS;
					if (sum > 0) {
						pointtransferMgmtService.transfer(commenterId, Pointtransfer.ID_C_SYS,
								Pointtransfer.TRANSFER_TYPE_C_AT_PARTICIPANTS, sum, commentId,
								System.currentTimeMillis());
					}

					return;
				}
			}

			final Set<String> atUserNames = userQueryService.getUserNames(commentContent);
			atUserNames.remove(commenterName);

			final Set<String> watcherIds = new HashSet<>();
			final JSONObject followerUsersResult = followQueryService
					.getArticleWatchers(UserExt.USER_AVATAR_VIEW_MODE_C_ORIGINAL, articleId, 1, Integer.MAX_VALUE);

			final List<JSONObject> watcherUsers = (List<JSONObject>) followerUsersResult.opt(Keys.RESULTS);
			for (final JSONObject watcherUser : watcherUsers) {
				final String watcherUserId = watcherUser.optString(Keys.OBJECT_ID);

				watcherIds.add(watcherUserId);
			}
			watcherIds.remove(articleAuthorId);

			if (commenterIsArticleAuthor && atUserNames.isEmpty() && watcherIds.isEmpty()
					&& StringUtils.isBlank(originalCmtId)) {
				return;
			}

			// 2. 'Commented' Notification
			if (!commenterIsArticleAuthor) {
				final JSONObject requestJSONObject = new JSONObject();
				requestJSONObject.put(Notification.NOTIFICATION_USER_ID, articleAuthorId);
				requestJSONObject.put(Notification.NOTIFICATION_DATA_ID, commentId);

				notificationMgmtService.addCommentedNotification(requestJSONObject);
			}

			// 3. 'Reply' Notification
			final Set<String> repliedIds = new HashSet<>();
			if (StringUtils.isNotBlank(originalCmtId)) {
				if (!articleAuthorId.equals(originalCmtAuthorId)) {
					final JSONObject requestJSONObject = new JSONObject();
					requestJSONObject.put(Notification.NOTIFICATION_USER_ID, originalCmtAuthorId);
					requestJSONObject.put(Notification.NOTIFICATION_DATA_ID, commentId);

					notificationMgmtService.addReplyNotification(requestJSONObject);

					repliedIds.add(originalCmtAuthorId);
				}
			}

			final String articleContent = originalArticle.optString(Article.ARTICLE_CONTENT);
			final Set<String> articleContentAtUserNames = userQueryService.getUserNames(articleContent);

			final Set<String> requisiteAtUserPermissions = new HashSet<>();
			requisiteAtUserPermissions.add(Permission.PERMISSION_ID_C_COMMON_AT_USER);
			final boolean hasAtUserPerm = roleQueryService.userHasPermissions(commenterId, requisiteAtUserPermissions);

			final Set<String> atIds = new HashSet<>();
			if (hasAtUserPerm) {
				// 4. 'At' Notification
				for (final String userName : atUserNames) {
					if (isDiscussion && !articleContentAtUserNames.contains(userName)) {
						continue;
					}

					final JSONObject user = userQueryService.getUserByName(userName);

					if (null == user) {
						LOGGER.log(Level.WARN, "Not found user by name [{0}]", userName);

						continue;
					}

					if (user.optString(Keys.OBJECT_ID).equals(articleAuthorId)) {
						continue; // Has notified in step 2
					}

					final String userId = user.optString(Keys.OBJECT_ID);
					if (repliedIds.contains(userId)) {
						continue;
					}

					final JSONObject requestJSONObject = new JSONObject();
					requestJSONObject.put(Notification.NOTIFICATION_USER_ID, userId);
					requestJSONObject.put(Notification.NOTIFICATION_DATA_ID, commentId);

					notificationMgmtService.addAtNotification(requestJSONObject);

					atIds.add(userId);
				}
			}

			// 5. 'following - article comment' Notification
			for (final String userId : watcherIds) {
				final JSONObject watcher = userRepository.get(userId);
				final String watcherName = watcher.optString(User.USER_NAME);

				if ((isDiscussion && !articleContentAtUserNames.contains(watcherName))
						|| commenterName.equals(watcherName) || repliedIds.contains(userId) || atIds.contains(userId)) {
					continue;
				}

				final JSONObject requestJSONObject = new JSONObject();
				requestJSONObject.put(Notification.NOTIFICATION_USER_ID, userId);
				requestJSONObject.put(Notification.NOTIFICATION_DATA_ID, commentId);

				notificationMgmtService.addFollowingArticleCommentNotification(requestJSONObject);
			}
		} catch (final Exception e) {
			LOGGER.log(Level.ERROR, "Sends the comment notification failed", e);
		}
	}

	/**
	 * Gets the event type {@linkplain EventTypes#ADD_COMMENT_TO_ARTICLE}.
	 *
	 * @return event type
	 */
	@Override
	public String getEventType() {
		return ADD_COMMENT_TO_ARTICLE;
	}
}
